1、 WORLDWIDE ENGINEERING STANDARDS Material Specification GMW16846 Desiccant for Use in Refrigerant Systems Using HFC-134a and HFO-1234yf Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 1 of 14 1 Scope Note: Nothing in this standard supercedes applicable laws and regulation
2、s. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Material Description. This standard describes the requirements of dehydrated, Zeolite or crystalline sodium or potassium-sodium alumino-silicate molecular sieves desiccants in
3、 bead form, suitable for use in Hydrofluoroolefin (HFO-1234yf), Haloalkane (HFC-134a) mobile air conditioning systems. 1.2 Symbols. Not applicable. 1.3 Typical Applications. Desiccants are used in automotive air conditioning systems to keep the refrigerant, lubricant, and components dry. Dryness is
4、necessary to minimize hydrate formation, corrosion, and chemical reactions that may degrade system materials. 1.4 Remarks. Not applicable. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ASHRAE 35-2010 ASTM D4179
5、 2.2 GM Standards/Specifications. GMW3059 2.3 Additional References. TMC003 Material Safety Data Sheet guidance documents (available at ). B 68800-63 Part Number for liners. National Institute of Standards and Technology. Scientific Specialties Service, Inc., Randallstown, MD. United States Standard
6、s Sieves. 3 Requirements 3.1 Bead Size. The size of the material as determined by analysis with United States Standard Sieves shall conform to the following: Through 6 mesh screen 100% weight minimum Through 8 mesh screen 90% weight minimum Retained on 12 mesh screen 90% weight minimum Retained on 2
7、0 mesh screen 99% weight minimum Retained on 30 mesh screen 99.9% weight minimum Through 100 mesh screen 0.02% weight maximum 3.1.1 Test Procedure for determination of compliance to 3.1 is in Appendix A. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot fo
8、r ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16846 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 2 of 14 3.2 Chemical Composition: The desiccant shall be anhydrous potassium sodium alumina silicate or
9、 zeolite. 80% K20, Na20, Al203, Si02, Zeolite, (Alumino silicate containing alkali oxides). 20% clay binder. Negligible active chemicals harmful in mobile air conditioning systems. 3.3 Density: The apparent bulk density shall not be less than 0.85 g/cc (53 lb/ft3). 3.3.1 Test Procedure. The Test Pro
10、cedure for determination of compliance to 3.3 is in Appendix B. 3.4 Bead Shape: The desiccant bead shape does not need to be perfect spheres, however, all surfaces on the beads shall be smooth and rounded. There shall be no significant amount of sharp edges. No more than 3% by weight of the beads sh
11、all be fractured. 3.5 Attrition. 3.5.1 Attrition Dry: The amount of 100 mesh or finer material will typically not exceed 1.0% by weight of the “as received” beads. 3.5.1.1 Test Procedure: Paint Shaker Test, Appendix C. 3.5.2 Attrition Fully Hydrated. The amount of 100 mesh or finer material will typ
12、ically not exceed 2.0% by weight of the hydrated beads. 3.5.2.1 Test Procedure Paint Shaker Test, Appendix D. 3.6 Water Test. Complete immersions of the “as received” desiccant beads in water shall not show any fracturing or exfoliation of the beads. There shall be no mushing or softening or dissolv
13、ing of the beads. 3.7 Bead Crush Test. The average force to fracture individual beads of an “as received” 25 bead sample shall be no less than 53 N (12 lb). 3.7.1 Test Procedure for determining compliance is ASTM D4179. 3.8 Water Content. The Loss on Ignition (LOI) of the “as received” desiccant mat
14、erial shall be a maximum of 1.5% by weight. LOI includes absorbed water plus chemically bound water and hydrocarbon residues present in the clay binder. 3.8.1 Test Procedure for determining compliance is found in Appendix E. 3.9 Water Absorption Capacity. 3.9.1 Water Capacity in Air. When tested in
15、air at 25 C (77 F) and 4.6 mm mercury (Hg) water vapor pressure, the dry desiccant shall absorb a minimum of 16.0 g of water per 100 g of dry desiccant. 3.9.1.1 Test Procedure for determining compliance is found in Appendix F. 3.9.2 Water Capacity in Liquid Refrigerant. In liquid HFO-1234yf and HFC-
16、134a at 60 C (140 F), the desiccant will have approximate water absorption equilibrium capacities at the listed water contents of the refrigerant, when tested according to ASHRAE 35-2010 (see Table 1). Table 1: Water Absorption Equilibrium Capacities 50 PPM (by weight) H2O in Liquid Desiccant H2O Ca
17、pacity, H2O/100 g Desiccant HFO-1234yf 16 HFC-134a 15 Note: This water capacity is the absolute water capacity of the desiccant in liquid refrigerant. To determine the useful water capacity in liquid refrigerant, subtract the “as received” water content of the desiccant, determined in 3.8 of this st
18、andard, and Appendix E. 3.10 Desiccant Chemical Compatibility. Chemical compatibility of the desiccant with the refrigerant and lubricant oil is an intrinsic property of the desiccant. Typically, the “as received” desiccant will contain 0.01% by weight of fluoride. Typically, desiccant exposed to HF
19、O-1234yf or HFC-134a refrigerant and lubricant oil will contain 0.10% by weight fluoride. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GM
20、W16846 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 3 of 14 3.10.1 Test Procedure for Determining Compliance, Appendix G. The desiccant chemical compatibility test, as described in 3.10, shall be performed at one (1) year intervals, or at any time, the manufacturing pr
21、ocess is changed in any way. 4 Manufacturing Process 4.1 Packaging 4.2 The desiccant shall be supplied in an airtight and moisture vapor proof container to prevent moisture pick-up during shipping and storage. 5 Rules and Regulations 5.1 Legal Regulations. All materials must satisfy applicable laws,
22、 rules, regulations and recommendations valid in the country of usage. 5.2 Language. In the event of conflict between the English and domestic language, the English language shall take precedence. 5.3 Inspection and Rejection. All shipments of material or parts under contract or purchase order manuf
23、actured to this specification shall be equivalent in every respect to the initial samples approved by Engineering. There shall be no changes in either formulation or manufacturing processes permitted without prior notification and approval by Engineering. Lack of notification by the supplier constit
24、utes grounds for rejection of any shipment. While samples may be taken from incoming shipments and checked for conformance to this specification, the supplier shall accept the responsibility for incoming shipments meeting this specification without dependence upon purchasers inspection. The series o
25、f tests used to approve each batch of product along with acceptance limits will be agreed upon by the purchaser and seller. The laboratory providing the certificate of analysis must also participate in a proficiency testing program (round robin) that is approved by the Fuels, Fluids, and Lubricants
26、Global Subsystem Leadership Team (GSSLT) or designate. The Fuels, Fluids, and Lubricants GSSLT or designate must receive copies of the proficiency testing reports directly from the test program administrator. 5.4 Initial Source Approval. No shipment shall be made by any supplier until representative
27、 initial production samples have been approved by the Fuels, Fluids, and Lubricants Global Subsystem Leadership Team or designees meeting the requirements of this specification. 5.5 Material Safety Data Sheets/Safety Data Sheets (MSDS/SDS). For new product submissions, or when a change in chemical c
28、omposition of an existing product has occurred, a complete copy of the Material Safety Data Sheet/Safety Data Sheet must be submitted in compliance with the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) requirements or other country-specific MSDS/SDS requirements. In a
29、ddition, product MSDS/SDS submissions must be in compliance with specific country General Motors TMC003 Material Safety Data Sheet/Safety Data Sheet guidance documents where available. 5.6 All materials supplied to this standard must comply with the requirements of GMW3059, Restricted and Reportable
30、 Substances for Parts. 6 Approved Sources Engineering qualifications of an approved source are required for this standard. Only sources listed in the GM Materials File (GM Supply Power) under this standard number have been qualified by Engineering as meeting the requirements of this standard. For ot
31、her GM locations, the responsible Engineering group should be contacted to obtain the approved source in that individual country. 7 Notes 7.1 Glossary. Not applicable. 7.2 Acronyms, Abbreviations, and Symbols. ASHRAE American Society of Heating Refrigerating and Air Conditioning Engineers ASTM ASTM
32、International GHS Globally Harmonized System of Classification and Labeling of Chemicals Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW
33、16846 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 4 of 14 GSSLT Global Subsystem Leadership Team HFC Haloalkane Refrigerant HFO Hydrofluoroolefin Refrigerant Hg Mercury ID Inner Diameter LOI Loss of Ignition MSDS Material Safety Data Sheet NIST National Institute of S
34、tandards and Technology OD Outer Diameter PPM Parts per Million PTFE Polytetrafluoroethylene SDS Safety Data Sheet SRM Standard Reference Material Wt Weight 8 Coding System This standard shall be referenced in other documents, drawings, etc., as follows: Material per GMW16846 9 Release and Revisions
35、 This standard was originated in August 2012. It was first approved by the Fuels, Fluids, and Lubricants Global Subsystem Leadership Team in January 2013. It was first published in January 2013. Issue Publication Date Description (Organization) 1 JAN 2013 Initial publication. Copyright General Motor
36、s Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16846 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 5 of 14 Appendix A A1 Bead Siz
37、e Test Method This procedure describes the method for determining the particle size distribution of molecular sieve bead products. A sample is placed on the top sieve of a nest, and the nest is shaken in a sieve-shaking apparatus for a specified time interval. The percentage of sample retained on ea
38、ch sieve is then calculated. A1.1 Apparatus. 1. Sieve-shaking apparatus, Ro-Tap or equivalent. 2. Automatic electric timer switch, 1 h by seconds. 3. Balance capable of 0.01 g. 4. Sieve, 203 mm (8 in) diameter, full height, U.S. Sieve Series. A1.2 Procedure. 1. The sieves to be used shall be nested
39、in order of decreasing sizes with the largest sieve on top and a receiving pan at the bottom. The sieves must be clean and dry. It is recommended that brass sieves be blown free of loose particles and dust, washed with a gentle stream of water, dried in an oven at approximately 100 C and cooled to r
40、oom temperature before using. 2. Weigh approximately 150 g of the sample, to 0.1 g and transfer to the top sieve of the nest. 3. Cover the nest, place in the Ro-Tap sieve shaking apparatus and shake for 5 minutes 5 seconds with the tapper in operation. 4. Weigh the sample on each sieve individually
41、to 0.05 g. 5. Calculate the percentage of sample retained on each pan using the sum of all individually retained weights as the total weight of the sample. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted
42、without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16846 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 6 of 14 Appendix B B1 Apparent Density To measure the bulk density of the product, a sample of known weight is placed into a graduated cylinder and tap
43、ped to a constant volume by an automatic tapper. B1.1 Apparatus. 1. Graduated cylinder (250 mL), approximately 27 mm (1 1/16 in) inner diameter (ID), plastic or Pyrex or equivalent. 2. Balance accurate to 0.1 g. 3. Tapping volumeter bulk density meter with counting device, or equivalent. B1.2 Proced
44、ure. 1 Weigh a clean, dry, 250 mL graduated cylinder to the nearest 0.1 g. 2 Fill the cylinder to approximately the 250 mL mark with sample to be tested and weigh again. 3 Secure the cylinder on the volumeter. Set the counting device for 5000 taps. Activate automatic tapper and repeat until the volu
45、me of sample remains constant between two (2) successive 5000 taps. 4 Read the volume of sample in the graduated cylinder and calculate the apparent density by the following formula. Apparent Density (g/mL) = (Weight of sample (g)/(Final volume of sample (mL) Note: The sample should be weighed immed
46、iately after the cylinder is filled so that moisture pick-up will not cause errors in the weight of the material. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE
47、ENGINEERING STANDARDS GMW16846 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 7 of 14 Appendix C C1 Attrition - Dry The attrition resistance of molecular sieve beads immersed in trichloroethylene is determined using this procedure. A measured volume of activated beads is
48、 placed in a glass jar and sufficient trichloroethylene is added to completely immerse the sample. Shake the sealed jar for 2 h on a Red Devil Paint Shaker. The amount of attrited 100 mesh material is then measured. C1.1 Apparatus. 1. Paint Shaker (Red Devil Model Number 5410) with a modified plywoo
49、d jar holder to hold two (2) jars, 67 mm (2 5/8 in) Outer Diameter (OD), shown in the Figure C1. 2. Glass jars with metal lids: wide mouth, approximately 177 mL (6 oz) capacity; 75 mm (2 15/16 in) inside depth, 59 mm (2 5/16 in) inside diameter. 3. Polytetrafluoroethylene (PTFE) cap liners to fit metal lids, 2 mm (1/16 in) thi
